To combat increasing electricity prices due to the high operating costs of conventional reverse cycle air-airheat pumps (RC-AA-HP), they can be powered by standalone PV systems as a radical demand side energy management solution. However, the heavy power consumption of their compressors necessitates very large and expensive standalone hotovoltaic (PV) systems. Alternatively, reversible air-water heat pumps (RCAW-HP) are integrated with thermal storage units, hence with downsized capacity RC-AW-HP but large thermal storage, the building thermal load can be handled equally.